The invention relates to an appliance for refuelling a gas fuel tank, having a compressor which can be driven via an electric motor, the suction side of which can be connected via a suction line provided with an inlet valve to a source of the gas fuel, in particular a natural gas line. The pressure side of the compressor can be connected to an intake line which can be coupled with the gas fuel tank to be refuelled, and is connected with an outlet line leading out of the pressurized tank via control and monitoring elements, which contain a relief valve disposed in a pressure chamber of a pressurized tank and a safety valve which can be set at a predetermined opening pressure.
A device of this type known from European Patent Application 0 300 222, has a compressor with a charging pressure which can be influenced via a control appliance as a function of the ambient temperature. The compressor and the motor are disposed next to the pressurized tank, which is divided by a partition into a fitting chamber connected with the pressure side of the compressor and a buffer chamber connected with the suction side of the compressor. The fitting chamber contains the inlet valve, the relief valve, a pressure control valve and further fittings, with it being possible to form the inlet valve and the relief valve by a common switching device. The buffer chamber is connected via connecting ducts constructed in the partition with the outlet sides of the inlet valve and of the relief valve and can be connected to the fitting chamber via a safety valve, which can be set at a relatively low opening pressure, e.g. 2 to 3 bar, to which chamber the outlet line is connected. When a predetermined charging pressure adapted to the ambient temperature is reached, which may be 100 to 200 bar, for example, with the known device the motor of the compressor is switched off via the control appliance and the relief valve is opened, with the amount of compressed gas fuel remaining in the compressor and in the intake line being guided into the buffer chamber, and when the pressure limited by the safety valve is exceeded, into the fitting chamber, and is discharged from said fitting chamber, decelerated by a throttle point, via the outlet line. Correspondingly, if a maximum value of the charging pressure set at the pressure control valve is exceeded, the amount of gas is guided away via the outlet line into the fitting chamber.
The known device requires a relatively large amount of space for the units to be arranged next to one another and to be connected to one another and that the design of the pressurized tank comprising two pressure-tight, explosion-proof tank parts is relatively lavish from the constructional viewpoint, with the partition constructed as a connecting part, especially as a distributor block.